1. Field of the Invention
The present invention relates to a digital demodulating apparatus that performs channel select processing and demodulation processing to a received signal that has been interleaved. The present invention relates also to a controlling method of the digital demodulating apparatus, a computer program product for the apparatus, a recording medium recording thereon the product, and a digital receiver.
2. Description of Related Art
A digital demodulating apparatus for demodulating a modulated signal, includes therein a tuner that performs channel select processing to the signal, and a demodulator that performs demodulation processing to the signal. A controller of the digital demodulating apparatus performs various controls for changing operation parameters of circuit elements that constitute the tuner and the demodulator.
However, some of the controls may cause errors in the signal being treated by the digital demodulating apparatus. JP-A-2001-251275 discloses a digital demodulating apparatus constructed so as to make a received signal hard to be affected by power control by turning the power of the apparatus on or off within each guard interval period.
However, the control of the digital demodulating apparatus of JP-A-2001-251275 can be performed only within each guard interval period. In addition, even when the control is performed within a guard interval period, there may be a case wherein the control affects the signal out of the guard interval period. If an error generated in the signal remains out of the guard interval period, it may bring about a problem that accurate information on, for example, an image or sound, can not be obtained from the signal demodulated.